Bi-specific antibodies comprising anti-b7h3 binding molecules

Abstract

A multi-specific antibody (e.g., bi-specific or tri-specific) comprising one antigen binding moiety specific to human B7H3 and one or more antigen binding moieties specific to one or more antigens of interest, for example, CD40, CD137, Glucocorticoid-Induced TNFR-Related protein (GITR), OX40, CD3, CD28, and CD47. Also provided herein are methods for preparing such antibodies and methods of using such for modulating immune responses.

1 . A multi-specific antibody, comprising:
 (a) a first antigen binding moiety binding to a first antigen, wherein the first antigen binding moiety comprising a first heavy chain variable region (V H ) and a first light chain variable region (V L ); and   (b) a second antigen binding moiety binding to a second antigen, wherein the second antigen binding moiety comprising a second V H  and a second V L ; and optionally   (c) a third antigen binding moiety binding to a third antigen, wherein the third antigen binding moiety comprising a third V H  and a third V L ;   wherein one of the first antigen and the second antigen is human B7H3 and the other one is selected from the group consisting of human CD40, human CD137, human Glucocorticoid-Induced TNFR-Related protein (GITR), human OX40, human CD3, human CD28, and human CD47; and   wherein the optional third antigen is selected from the group consisting of human CD40, human CD137, human Glucocorticoid-Induced TNFR-Related protein (GITR), human OX40, human CD3, human CD28, and human CD47; the optional third antigen being different from the first antigen and the second antigen.   
     
     
         2 . The multi-specific antibody of  claim 1 , wherein the antigen binding moiety that binds B7H3 comprises (i) a heavy chain variable region (V H ) that comprises the same heavy chain complementary determining regions (CDRs) as antibody B7H3 Ab1 or B7H3 Ab2, and (ii) a light chain variable region (V L ) that comprises the same light chain CDRs as antibody B7H3 Ab1 or B7H3 Ab2. 
     
     
         3 . The multi-specific antibody of  claim 1 , wherein the antigen binding moiety that binds B7H3 comprises (i) a heavy chain variable region (V H ) that comprises heavy chain complementary determining regions (CDRs), which collectively contain up to 5 amino acid residue variations relative to the heavy chain CDR3 of antibody B7H3 Ab1 or B7H3 Ab2, and (ii) a light chain variable region (V L ) that comprises light chain CDRs, which collectively contain up to 5 amino acid residue variations relative to the light chain CDRs of antibody B7H3 Ab1 or B7H3 Ab2. 
     
     
         4 . The multi-specific antibody of  claim 3 , wherein the antigen binding moiety that binds B7H3 comprises (i) the V H  that comprises an amino acid sequence at least 80% identical to that of antibody B7H3 Ab1 or B7H3 Ab2; and (ii) the V L  that comprises an amino acid sequence at least 80% identical to that of antibody B7H3 Ab1 or B7H3 Ab2. 
     
     
         5 . The multi-specific antibody of  claim 4 , wherein the antigen binding moiety that binds B7H3 comprises the same V H  and same V L  as antibody B7H3 Ab1 or B7H3 Ab2. 
     
     
         6 . The multi-specific antibody of  claim 1 , wherein the antigen binding moieties that bind human CD40, human CD137, human Glucocorticoid-Induced TNFR-Related protein (GITR), human OX40, human CD3, human CD28, or human CD47 each comprise (i) a heavy chain variable region (V H ) that comprises the same heavy chain complementary determining regions (CDRs) as antibody CD40 Ab1, CD137 Ab1, GITR Ab1, OX40 Ab1, CD28 Ab1, CD28 Ab2, CD28 Ab3, CD47 Ab1, CD47 Ab2, CD3 Ab1, or CD3 Ab2; and (ii) a light chain variable region (V L ) that comprises the same light chain CDRs as antibody CD40 Ab1, CD137 Ab1, GITR Ab1, OX40 Ab1, CD28 Ab1, CD28 Ab2, CD28 Ab3, CD47 Ab1, CD47 Ab2, CD3 Ab1, or CD3 Ab2. 
     
     
         7 . The multi-specific antibody of  claim 1 , wherein the antigen binding moieties that bind human CD40, human CD137, human Glucocorticoid-Induced TNFR-Related protein (GITR), human OX40, human CD3, human CD28, or human CD47 each comprise:
 (i) a heavy chain variable region (V H ) that comprises heavy chain complementary determining regions (CDRs), which collectively contain up to 5 amino acid residue variations relative to the heavy chain CDR3 of antibody CD40 Ab1, CD137 Ab1, GITR Ab1, OX40 Ab1, CD28 Ab1, CD28 Ab2, CD28 Ab3, CD47 Ab1, CD47 Ab2, CD3 Ab1, or CD3 Ab2; and   (ii) a light chain variable region (V L ) that comprises light chain CDRs, which collectively contain up to 5 amino acid residue variations relative to the light chain CDRs of CD40 Ab1, CD137 Ab1, GITR Ab1, OX40 Ab1, CD28 Ab1, CD28 Ab2, CD28 Ab3, CD47 Ab1, CD47 Ab2, CD3 Ab1, or CD3 Ab2.   
     
     
         8 . The multi-specific antibody of  claim 7 , wherein the antigen binding moieties that bind human CD40, human CD137, human Glucocorticoid-Induced TNFR-Related protein (GITR), human OX40, human CD3, human CD28, or human CD47 each comprise:
 (i) the V H  that comprises an amino acid sequence at least 80% identical to that of antibody CD40 Ab1, CD137 Ab1, GITR Ab1, OX40 Ab1, CD28 Ab1, CD28 Ab2, CD28 Ab3, CD47 Ab1, CD47 Ab2, CD3 Ab1, or CD3 Ab2; and   (ii) the V L  that comprises an amino acid sequence at least 80% identical to that of antibody CD40 Ab1, CD137 Ab1, GITR Ab1, OX40 Ab1, CD28 Ab1, CD28 Ab2, CD28 Ab3, CD47 Ab1, CD47 Ab2, CD3 Ab1, or CD3 Ab2.   
     
     
         9 . The multi-specific antibody of  claim 8 , wherein the antigen binding moieties that bind human CD40, human CD137, human Glucocorticoid-Induced TNFR-Related protein (GITR), human OX40, human CD3, human CD28, or human CD47 each comprise the same V H  and same V L  as antibody CD40 Ab1, CD137 Ab1, GITR Ab1, OX40 Ab1, CD28 Ab1, CD28 Ab2, CD28 Ab3, CD47 Ab1, CD47 Ab2, CD3 Ab1, or CD3 Ab2. 
     
     
         10 . The multi-specific antibody of  claim 1 , which is a bi-specific antibody that comprises the first antigen binding moiety and the second antigen binding moiety. 
     
     
         11 . The multi-specific antibody of  claim 10 , wherein the bi-specific antibody is of a two-chain format. 
     
     
         12 . The multi-specific antibody of  claim 11 , wherein (i) the first antigen binding moiety comprises a heavy chain that comprises the first V H  and a heavy chain constant region or a fragment thereof and a light chain that comprises the first V L  and a light chain constant region; and (ii) the second antigen binding moiety is a single chain variable fragment (scFv); and wherein the scFv is linked to either the heavy chain or the light chain of (i). 
     
     
         13 . The multi-specific antibody of  claim 12 , wherein the scFv is linked to the N-terminus of the heavy chain of (i) or the C-terminus of the heavy chain. 
     
     
         14 . The multi-specific antibody of  claim 12 , which comprises a first polypeptide that comprises the heavy chain of (i) fused to the scFv, and a second polypeptide that comprises the light chain of (i). 
     
     
         15 . The multi-specific antibody of  claim 12 , which comprises a first polypeptide that comprise the heavy chain of (i); and a second polypeptide that comprises the light chain of (i) fused to the scFv. 
     
     
         16 . The multi-specific antibody of  claim 12 , wherein the first antigen binding moiety binds B7H3. 
     
     
         17 . The multi-specific antibody of  claim 14 , wherein the multi-specific antibody is a multi-chain complex comprising two copies of each of the first polypeptide and the second polypeptide. 
     
     
         18 . The multi-specific antibody of  claim 10 , which is of a three-chain format. 
     
     
         19 . The multi-specific antibody of  claim 18 , which comprises:
 (i) a first polypeptide that comprise a first heavy chain of the first antigen binding moiety, wherein the first heavy chain comprises the first V H  and a first heavy chain constant region or a fragment comprising the CH3 domain therein,   (ii) a second polypeptide that comprises a second heavy chain of the first antigen binding moiety and the second antigen binding moiety, which is a single chain variable fragment (scFv) comprising the second V H  and second V L , wherein the second heavy chain comprises the first V H  and a second heavy chain constant region or a fragment comprising the CH3 domain therein; and   (iii) a third polypeptide that comprises a light chain of the first antigen binding moiety, which comprises the first V L  and a light chain constant region;   optionally wherein the first and second heavy chain constant regions comprise mutations in the CH3 domains that enhances heterodimeration over homodimeration as relative to the wild-type counterpart and/or reduces protein A binding.   
     
     
         20 . The multi-specific antibody of  claim 19 , wherein in (ii), the scFv is located between the first V H  and the second Fc fragment or the CH3 domain thereof. 
     
     
         21 . The multi-specific antibody of  claim 19 , wherein in (ii), the scFv is located at the C-terminus of the second polypeptide. 
     
     
         22 . The multi-specific antibody of  claim 18 , which comprises:
 (i) a first polypeptide that comprise a first heavy chain of the first antigen binding moiety and one of the second V H  and the second V L  of the second antigen binding moiety; wherein the first heavy chain comprises the first V H  and a first heavy chain constant region or a fragment comprising the CH3 domain therein,   (ii) a second polypeptide that comprises a second heavy chain of the first antigen binding moiety and the other one of the second V H  and second V L  of the second antigen binding moiety, wherein the second heavy chain comprises the first V H  and a second heavy chain constant region or a fragment comprising the CH3 domain therein; and   (iii) a third polypeptide that comprises a light chain of the first antigen binding moiety, which comprises the first V L  and a light chain constant region;   optionally wherein the first and second heavy chain constant regions comprise mutations in the CH3 domains that enhances heterodimeration over homodimeration as relative to the wild-type counterpart.   
     
     
         23 . The multi-specific antibody of  claim 19 , wherein the first and second heavy chain constant regions comprise the mutations, which are knob-in-hole mutations, charged mutations, or ZW1 mutations. 
     
     
         24 . The multi-specific antibody of  claim 19 , wherein one of the first and second heavy chain constant regions comprises a mutation that reduces protein A binding activity relative to the wild-type counterpart. 
     
     
         25 . The multi-specific antibody of  claim 10 , which is of a four-chain format. 
     
     
         26 . The multi-specific antibody of  claim 25 , which comprises:
 (i) a first polypeptide comprising a first heavy chain of the first antigen binding moiety, the first heavy chain comprising the first V H  and a first heavy chain constant region or a fragment comprising the CH3 domain therein;   (ii) a second polypeptide comprising a second heavy chain of the second antigen binding moiety, the second heavy chain comprising the second V H , a light chain constant region, and a second heavy chain constant fragment comprising a CH3 domain;   (iii) a third polypeptide comprising a light chain of the first antigen moiety, which comprises the first V L  and a light chain constant region; and   (iv) a fourth polypeptide comprising a light chain of the second antigen moiety, the light chain comprising the second V L  linked to a CH1 domain of a heavy chain constant region;   optionally wherein the first and second heavy chain constant regions comprise mutations in the CH3 domains that enhances heterodimeration over homodimeration as relative to the wild-type counterpart.   
     
     
         27 . The multi-specific antibody of  claim 25 , which comprises:
 (i) a first polypeptide comprising a first heavy chain of the first antigen binding moiety, wherein the first heavy chain comprises the first V H  and a first heavy chain constant region or a fragment comprising the CH3 domain therein;   (ii) a second polypeptide comprising a second heavy chain, which comprises the first V H , the second antibody binding moiety that is a scFv fragment comprising the second V H  and the second V L , and a second heavy chain constant region or a fragment comprising the CH3 domain therein;   (iii) a third polypeptide comprising a light chain of the first antigen binding moiety, which comprises the first V L  and a light chain constant region; and   (iv) a fourth polypeptide comprising the scFv;   optionally wherein the first and second heavy chain constant regions comprise mutations in the CH3 domains that enhances heterodimeration over homodimeration as relative to the wild-type counterpart.   
     
     
         28 . The multi-specific antibody of  claim 25 , which comprises:
 (i) a first polypeptide comprising a first heavy chain of the first antigen binding moiety, wherein the first heavy chain comprises the first V H  and a first heavy chain constant region or a fragment comprising the CH3 domain therein;   (ii) a second polypeptide comprising a light chain of the first antigen binding moiety, which comprises the first V L  and a light chain constant region;   (iii) a third polypeptide comprising the second V H , a first TCR fragment, and a second heavy chain constant fragment comprising a CH3 domain; and   (iv) a fourth polypeptide comprising the second V L  and a second TCR fragment;   wherein the first and second TCR fragments collectively are a TCR alpha chain fragment and a TCR beta chain fragment, which form a dimer; and   optionally wherein the first and second heavy chain constant regions comprise mutations in the CH3 domains that enhances heterodimeration over homodimeration as relative to the wild-type counterpart.   
     
     
         29 . The multi-specific antibody of  claim 28 , wherein the third polypeptide further comprises the first V H  linked to a CH1 domain of a heavy chain constant region. 
     
     
         30 . The multi-specific antibody of  claim 25 , wherein the first and second heavy chain constant regions comprise the mutations, which are knob-in-hole mutations, charged mutations, or ZW1 mutations. 
     
     
         31 . The multi-specific antibody of  claim 25 , wherein one of the first and second heavy chain constant regions comprises a mutation that reduces protein A binding activity relative to the wild-type counterpart. 
     
     
         32 . The multi-specific antibody of  claim 11 , which is a bi-specific antibody comprising the first antigen binding moiety that binds B7H3 and the second antigen binding moiety that binds CD40. 
     
     
         33 . The multi-specific antibody of  claim 32 , which is selected from the group consisting of Ly1581, Ly1660, Ly1661, Ly1662, Ly1663, Ly1679, Ly1935, and Ly1936. 
     
     
         34 . The multi-specific antibody of  claim 11 , which is a bi-specific antibody comprising the first antigen binding moiety that binds B7H3 and the second antigen binding moiety that binds CD137. 
     
     
         35 . The multi-specific antibody of  claim 34 , which is selected from the group consisting of Ly1937, Ly1938, Ly1939, Ly1940, Ly1941, Ly1942, Ly1943, and Ly1944. 
     
     
         36 . The multi-specific antibody of  claim 11 , which is a bi-specific antibody comprising the first antigen binding moiety that binds B7H3 and the second antigen binding moiety that binds GITR. 
     
     
         37 . The multi-specific antibody of  claim 36 , which is selected from the group consisting of Ly1945, Ly1946, Ly1947, Ly1948, Ly1049, Ly1950, Ly1951, and Ly1952. 
     
     
         38 . The multi-specific antibody of  claim 11 , which is a bi-specific antibody comprising the first antigen binding moiety that binds B7H3 and the second antigen binding moiety that binds OX40. 
     
     
         39 . The multi-specific antibody of  claim 38 , which is selected from the group consisting of Ly1953, Ly1954, Ly1955, Ly1956, Ly1957, Ly1958, Ly1959, and Ly1960. 
     
     
         40 . The multi-specific antibody of  claim 11 , which is a bi-specific antibody comprising the first antigen binding moiety that binds B7H3 and the second antigen binding moiety that binds CD47. 
     
     
         41 . The multi-specific antibody of  claim 40 , which is selected from the group consisting of Ly2043, Ly2044, Ly2045, Ly2046, Ly2047, Ly2048, Ly2049, Ly2050, Ly2051, Ly2052, Ly2053, Ly2054, Ly2055, Ly2056, Ly2057, Ly2058, Ly2059, Ly2060, Ly2061, Ly2062, Ly2063, and Ly2064. 
     
     
         42 . The multi-specific antibody of  claim 11 , which is a bi-specific antibody comprising the first antigen binding moiety that binds B7H3 and the second antigen binding moiety that binds CD3. 
     
     
         43 . The multi-specific antibody of  claim 42 , which is selected from the group consisting of Ly1900, Ly1901, Ly1902, Ly1903, and Ly1904. 
     
     
         44 . The multi-specific antibody of  claim 1 , which is a tri-specific antibody that comprises (i) the first antigen binding moiety, (ii) the second antigen binding moiety, and (iii) the third antigen binding moiety. 
     
     
         45 . The multi-specific antibody of  claim 44 , which comprises:
 (i) a first polypeptide comprising a first heavy chain that comprises the first V H  of the first antigen binding moiety and first heavy chain constant region or a fragment comprising the CH3 domain therein;   (ii) a second polypeptide comprising the first V H , a second heavy chain comprising the second V H  of the second antigen binding moiety and a light chain constant region, and a second heavy chain constant region or a fragment comprising the CH3 domain therein;   (iii) a third polypeptide comprising a light chain of the first antigen binding moiety, which comprises the first V L  and a light chain constant region; and   (iv) a fourth polypeptide comprising the second V L  of the second antigen binding moiety and a CH1 fragment of a heavy chain constant region;   wherein the first polypeptide, the second polypeptide or both further comprise the third antigen binding moiety, which is a single chain variable fragment (scFv);   optionally wherein the first and second heavy chain constant regions comprise mutations in the CH3 domains that enhances heterodimeration over homodimeration as relative to the wild-type counterpart.   
     
     
         46 . The multi-specific antibody of  claim 44 , which comprises:
 (i) a first polypeptide comprising a first heavy chain that comprises the first V H  of the first antigen binding moiety and a first heavy chain constant region or a fragment comprising the CH3 domain therein;   (ii) a second polypeptide comprising the first V H , a second heavy chain comprising the second V L  of the second antigen binding moiety and a CH1 domain of a heavy chain constant region, and a second heavy chain constant region or a fragment comprising the CH3 domain therein;   (iii) a third polypeptide comprising a light chain of the first antigen binding moiety; and   (iv) a fourth polypeptide comprising the second V H  of the second antigen binding moiety and a light chain constant region;   wherein the first polypeptide, the second polypeptide or both further comprise the third antigen binding moiety, which is a single chain variable fragment (scFv); and   optionally wherein the first and second heavy chain constant regions comprise mutations in the CH3 domains that enhances heterodimeration over homodimeration as relative to the wild-type counterpart.   
     
     
         47 . The multi-specific antibody of  claim 44 , which comprises:
 (i) a first polypeptide comprising a first heavy chain that comprises the first V H  of the first antigen binding moiety, first heavy chain constant region or a fragment comprising the CH3 domain therein, and one of the third V H  and third V L  of the third antigen binding moiety;   (ii) a second polypeptide comprising the first V H , a second heavy chain comprising the second V H  of the second antigen binding moiety and a light chain constant region, a second heavy chain constant region or a fragment comprising the CH3 domain therein, and the other one of the third V H  and third V L ;   (iii) a third polypeptide comprising a light chain of the first antigen binding moiety, which comprises the first V L  and a light chain constant region; and   (iv) a fourth polypeptide comprising the second V L  of the second antigen binding moiety and a CH1 domain of a heavy chain constant region;   optionally wherein the first and second heavy chain constant regions comprise mutations in the CH3 domains that enhances heterodimeration over homodimeration as relative to the wild-type counterpart.   
     
     
         48 . The multi-specific antibody of  claim 44 , which comprises:
 (i) a first polypeptide comprising a first heavy chain that comprises the first V H  of the first antigen binding moiety, a first heavy chain constant region or a fragment comprising the CH3 domain therein, and one of the third V H  and third V L  of the third antigen binding moiety;   (ii) a second polypeptide comprising the first V H , a second heavy chain comprising the second V L  of the second antigen binding moiety and a CH1 domain of a heavy chain constant region, a second heavy chain constant region or a fragment comprising the CH3 domain therein, and the other one of the third V H  and third V L ;   (iii) a third polypeptide comprising a light chain of the first antigen binding moiety, which comprises the first V L  and a light chain constant region; and   (iv) a fourth polypeptide comprising the second V H  of the second antigen binding moiety and a light chain constant region;   optionally wherein the first and second heavy chain constant regions comprise mutations in the CH3 domains that enhances heterodimeration over homodimeration as relative to the wild-type counterpart.   
     
     
         49 . The multi-specific antibody of  claim 44 , which comprises:
 (i) a first polypeptide comprising a first heavy chain that comprises the first V H  of the first antigen binding moiety and a first heavy chain constant region or a fragment comprising the CH3 domain therein;   (ii) a second polypeptide comprising the first V H , the second antigen binding moiety, which is a scFv, and a second heavy chain constant region or a fragment comprising the CH3 domain therein; and   (iii) a third polypeptide comprising a light chain of the first antigen binding moiety, which comprises the first V L  and a light chain constant region;   wherein the first polypeptide, the second polypeptide, or both further comprise the third antigen binding moiety, which is a scFv; and   optionally wherein the first and second heavy chain constant regions comprise mutations in the CH3 domains that enhances heterodimeration over homodimeration as relative to the wild-type counterpart.   
     
     
         50 . The multi-specific antibody of  claim 44 , which comprises:
 (i) a first polypeptide comprising a first heavy chain that comprises the first V H  of the first antigen binding moiety, one of the second V H  and second V L  of the second antigen binding moiety, and a first heavy chain constant region or a fragment comprising the CH3 domain therein;   (ii) a second polypeptide comprising the first V H , the other one of the second V H  and second V L , and a second heavy chain constant region or a fragment comprising the CH3 domain therein; and   (iii) a third polypeptide comprising a light chain of the first antigen binding moiety, which comprises the first V L  and a light chain constant region;   wherein the first polypeptide, the second polypeptide, or both further comprise the third antigen binding moiety, which is a scFv, or wherein the third polypeptide further comprises the third antigen binding moiety; and   optionally wherein the first and second heavy chain constant regions comprise mutations in the CH3 domains that enhances heterodimeration over homodimeration as relative to the wild-type counterpart.   
     
     
         51 . The multi-specific antibody of  claim 44 , which comprises:
 (i) a first polypeptide comprising a first heavy chain that comprises the first V H  of the first antigen binding moiety, one of the second V H  and second V L  of the second antigen binding moiety, a first heavy chain constant region or a fragment comprising the CH3 domain therein, and one of the third V H  and third V L  of the third antigen binding moiety;   (ii) a second polypeptide comprising the first V H , the other one of the second V H  and second V L , and a second heavy chain constant region or a fragment comprising the CH3 domain therein, and the other one of the third V H  and third V L ; and   (iii) a third polypeptide comprising a light chain of the first antigen binding moiety, which comprises the first V L  and a light chain constant region;   optionally wherein the first and second heavy chain constant regions comprise mutations in the CH3 domains that enhances heterodimeration over homodimeration as relative to the wild-type counterpart.   
     
     
         52 . The multi-specific antibody of  claim 44 , which comprises:
 (i) a first polypeptide comprising a first heavy chain that comprises the first V H  of the first antigen binding moiety, a first heavy chain constant region or a fragment comprising the CH3 domain therein, and the second antigen binding moiety, which is a scFv;   (ii) a second polypeptide comprising the first V H , a second heavy chain constant region or a fragment comprising the CH3 domain therein, and the third antigen binding moiety, which is a scFv; and   (iii) a third polypeptide comprising a light chain of the first antigen binding moiety, which comprises the first V L  and a light chain constant region;   optionally wherein the first and second heavy chain constant regions comprise mutations in the CH3 domains that enhances heterodimeration over homodimeration as relative to the wild-type counterpart.   
     
     
         53 . The multi-specific antibody of  claim 44 , which comprises:
 (i) a first polypeptide comprising a first heavy chain that comprises the first V H  of the first antigen binding moiety and a first heavy chain constant region or a fragment comprising the CH3 domain therein;   (ii) a second polypeptide comprising a second heavy chain that comprises the second V H  of the second antigen binding moiety and one of the third V H  and third V L  of the third antigen binding moiety, wherein the third V H  is fused with a light chain constant region or the third V L  is fused with a CH1 domain of a heavy chain constant region;   (iii) a third polypeptide comprising a light chain of the second antigen binding moiety, which comprises the second V L  and a light chain constant region, and the other one of the third V H  and third V L  of the third antigen binding moiety, wherein the third V H  is fused with a light chain constant region or the third V L  is fused with a CH1 domain of a heavy chain constant region; and   (iv) a fourth polypeptide comprising a light chain of the first antigen binding moiety, which comprises the first V L  and a light chain constant region;   wherein either the second polypeptide or the third polypeptide further comprise a second heavy chain constant region or a fragment comprising the CH3 domain therein; and   optionally wherein the first and second heavy chain constant regions comprise mutations in the CH3 domains that enhances heterodimeration over homodimeration as relative to the wild-type counterpart.   
     
     
         54 . The multi-specific antibody of  claim 44 , which comprises:
 (i) a first polypeptide comprising the first V H  of the first antigen binding moiety, the second V H  of the second antigen binding moiety, and a first heavy chain constant region or a fragment comprising the CH3 domain therein;   (ii) a second polypeptide comprising the third V H  of the third antigen binding moiety and a light chain constant domain;   (iii) a third polypeptide comprising the third V L  of the third antigen binding moiety and a CH1 domain of a heavy chain constant region; and   (iv) a fourth polypeptide comprising a light chain of the first antigen binding moiety, which comprises the first V L  and a light chain constant region;   wherein either the second polypeptide or the third polypeptide further comprise the second V L  of the second antigen binding moiety and a second heavy chain constant region or a fragment comprising the CH3 domain therein; and   optionally wherein the first and second heavy chain constant regions comprise mutations in the CH3 domains that enhances heterodimeration over homodimeration as relative to the wild-type counterpart.   
     
     
         55 . The multi-specific antibody of  claim 44 , which comprises:
 (i) a first polypeptide comprising the first V H  of the first antigen binding moiety, the second V L  of the second antigen binding moiety, and a first heavy chain constant region or a fragment comprising the CH3 domain therein;   (ii) a second polypeptide comprising the third V H  of the third antigen binding moiety and a light chain constant domain;   (iii) a third polypeptide comprising the third V L  of the third antigen binding moiety and a CH1 domain of a heavy chain constant region; and   (iv) a fourth polypeptide comprising a light chain of the first antigen binding moiety, which comprises the first V L  and a light chain constant region;   wherein either the second polypeptide or the third polypeptide further comprise the second V H  of the second antigen binding moiety and a second heavy chain constant region or a fragment comprising the CH3 domain therein;   optionally wherein the first and second heavy chain constant regions comprise mutations in the CH3 domains that enhances heterodimeration over homodimeration as relative to the wild-type counterpart.   
     
     
         56 . The multi-specific antibody of  claim 54 , wherein either the second polypeptide or the third polypeptide further comprises the first V H  fused to a CH1 of a heavy chain constant region. 
     
     
         57 . The multi-specific antibody of  claim 44 , which comprises:
 (i) a first polypeptide comprising a heavy chain of the 1 st  antigen binding moiety and the second antigen binding moiety, wherein the heavy chain of the 1 st  antigen binding moiety comprises the first V H  and a heavy chain constant region, and wherein the second antigen binding moiety is an scFv fragment; and   (ii) a second polypeptide comprising a light chain of the 1 st  antigen binding moiety and the third antigen binding moiety, wherein the light chain comprises the first V L  and a light chain constant region, and wherein the third antigen binding moiety is an scFv fragment.   
     
     
         58 . The multi-specific antibody of  claim 44 , which comprises:
 (i) a first polypeptide comprising a heavy chain of the 1 st  antigen binding moiety and the second antigen binding moiety, wherein the heavy chain of the 1 st  antigen binding moiety comprises the first V H  and a first heavy chain constant region, and wherein the second antigen binding moiety is an scFv fragment; and   (ii) a second polypeptide comprising a heavy chain of the 1 st  antigen binding moiety and the third antigen binding moiety, wherein the heavy chain comprises the first V H  and a second heavy chain constant region, and wherein the third antigen binding moiety is an scFv fragment; and   (iii) a third polypeptide comprising a light chain of the first antigen binding moiety, the light chain comprising the first V L  and a light chain constant region;   optionally wherein the first and second heavy chain constant regions comprise mutations in the CH3 domains that enhances heterodimeration over homodimeration as relative to the wild-type counterpart.   
     
     
         59 . The multi-specific antibody of  claim 45 , wherein the first and second heavy chain constant regions comprise the mutations, which are knob-in-hole mutations, charged mutations, or ZW1 mutations. 
     
     
         60 . The multi-specific antibody of  claim 45 , wherein one of the first and second heavy chain constant regions comprises a mutation that reduces protein A binding activity relative to the wild-type counterpart. 
     
     
         61 . The multi-specific antibody of  claim 44 , which is a tri-specific antibody comprising (i) the first antigen binding moiety, (ii) the second antigen binding moiety, and (iii) the third antigen binding moiety, wherein (i)-(iii) bind B7H3, CD3, and CD137. 
     
     
         62 . The multi-specific antibody of  claim 61 , which is selected from the group consisting of Ly1785, Ly1793, Ly1794, Ly1795, Ly1796, Ly1797, Ly1798, Ly1799, Ly1800, Ly1801, Ly1802, Ly1803, Ly1804, Ly1805, and Ly1849. 
     
     
         63 . The multi-specific antibody of  claim 44 , which is a tri-specific antibody comprising (i) the first antigen binding moiety, (ii) the second antigen binding moiety, and (iii) the third antigen binding moiety, wherein (i)-(iii) bind B7H3, CD3, and GITR. 
     
     
         64 . The multi-specific antibody of  claim 63 , which is selected from the group consisting of Ly1905, Ly1906, Ly1907, Ly1908, Ly1909, Ly1910, Ly1911, Ly1912, Ly1913, Ly1914, Ly1915, Ly1916, Ly1917, Ly1918, and Ly1933. 
     
     
         65 . The multi-specific antibody of  claim 44 , which is a tri-specific antibody comprising (i) the first antigen binding moiety, (ii) the second antigen binding moiety, and (iii) the third antigen binding moiety, wherein (i)-(iii) bind B7H3, CD3, and OX40. 
     
     
         66 . The multi-specific antibody of  claim 65 , which is selected from the group consisting of Ly1919, Ly1920, Ly1921, Ly1922, Ly1923, Ly1924, Ly1925, Ly1926, Ly1927, Ly1928, Ly1929, Ly1930, Ly1931, Ly1932, and Ly1934. 
     
     
         67 . The multi-specific antibody of  claim 44 , which is a tri-specific antibody comprising (i) the first antigen binding moiety, (ii) the second antigen binding moiety, and (iii) the third antigen binding moiety, wherein (i)-(iii) bind B7H3, CD3, and CD28. 
     
     
         68 . The multi-specific antibody of  claim 67 , which is selected from the group consisting of Ly1968-Ly2042. 
     
     
         69 . The multi-specific antibody of  claim 44 , which is a tri-specific antibody comprising (i) the first antigen binding moiety, (ii) the second antigen binding moiety, and (iii) the third antigen binding moiety, wherein (i)-(iii) bind B7H3, CD137, and OX40. 
     
     
         70 . The multi-specific antibody of  claim 69 , which is Ly2076, Ly2077, or Ly2078. 
     
     
         71 . The multi-specific antibody of  claim 44 , which is a tri-specific antibody comprising (i) the first antigen binding moiety, (ii) the second antigen binding moiety, and (iii) the third antigen binding moiety, wherein (i)-(iii) bind B7H3, CD137, and GITR. 
     
     
         72 . The multi-specific antibody of  claim 71 , which is Ly2079, Ly2080, or Ly2081. 
     
     
         73 . A humanized antibody specific to human B7H3, wherein the humanized antibody comprises a heavy chain variable region (V H ) and a light chain variable region (V L ), wherein:
 (i) the V H  comprises a framework of IGHV1-46*01 and heavy chain complementary determining regions (CDRs) 1, 2, and 3, which are either identical to those of parent murine antibody Ly383 or collectively contain no more than 5 amino acid residue variations relative to the parent murine antibody Ly383; or   (ii) the V H  comprises a framework of IGHV1-2*02 and heavy chain CDRs 1, 2, and 3, which are either identical to those of parent murine antibody Ly387 or collectively contain no more than 5 amino acid residue variations relative to the parent murine antibody Ly387.   
     
     
         74 . The humanized antibody of  claim 73 , wherein the V L  comprises a framework of IGKV3-11*01 and light chain CDRs 1, 2, and 3, which are either identical to those of the parent murine antibody Ly383 or Ly387 or collectively contain no more than 5 amino acid residue variations relative to the parent murine antibody Ly383 or Ly387. 
     
     
         75 . The humanized antibody of  claim 73 , wherein the antibody comprises the same heavy chain CDRs 1, 2, and 3 as antibody Ly383, and/or the same light chain CDRs 1, 2, and 3 and antibody Ly383. 
     
     
         76 . The humanized antibody of  claim 73 , wherein the antibody comprises the same heavy chain CDRs 1, 2, and 3 as antibody Ly387, and/or the same light chain CDRs 1, 2, and 3 and antibody Ly387. 
     
     
         77 . The humanized antibody of  claim 75 , wherein the V H  comprises one or more mutations in the V H  framework. 
     
     
         78 . The humanized antibody of  claim 77 , wherein the mutations in the V H  framework are back mutations based on amino acid residues in the parent murine antibody at corresponding positions. 
     
     
         79 . The humanized antibody of  claim 73 , wherein the V H  comprises the amino acid sequence of SEQ ID NO: 35, 39, 47, or 49; and/or wherein the V L  comprises the amino acid sequence of SEQ ID NO: 37 or 41. 
     
     
         80 . The humanized antibody of  claim 73 , wherein the V H  comprises the amino acid sequence of SEQ ID NO: 43; and/or wherein the V L  comprises the amino acid sequence of SEQ ID NO: 45. 
     
     
         81 . The humanized antibody of  claim 73 , wherein the antibody is a full-length antibody. 
     
     
         82 . The humanized antibody of  claim 81 , wherein the full-length antibody is an IgG/kappa molecule. 
     
     
         83 . The humanized antibody of  claim 82 , wherein the full-length antibody comprises a heavy chain that is an IgG1, IgG2, or IgG4 chain. 
     
     
         84 . The humanized antibody of  claim 83 , wherein the heavy chain comprises a mutated Fc region, which exhibits altered binding affinity or selectivity to an Fc receptor as relative to the wild-type counterpart. 
     
     
         85 . The humanized antibody of  claim 73 , wherein the antibody is selected from the group consisting of Ly1426, Ly1562, Ly1612, Ly1614, Ly1616, Ly1618, and Ly1442. 
     
     
         86 . A nucleic acid or a nucleic acid set, which collectively encodes an antibody of  any one of the preceding claims . 
     
     
         87 . The nucleic acid or nucleic acid set of  claim 86 , which is an expression vector or an expression vector set. 
     
     
         88 . A host cell, comprising the nucleic acid or nucleic acid set of  claim 86 . 
     
     
         89 . The host cell of  claim 88 , which is a mammalian host cell. 
     
     
         90 . A method for producing an antibody set forth in  claim 1 :
 (i) culturing the host cell of comprising a nucleic acid(s) encoding the antibody under conditions allowing for expression of the antibody; and   (ii) harvesting the antibody thus produced.   
     
     
         91 . A pharmaceutical composition comprising an antibody of  claim 1  and a pharmaceutically acceptable carrier. 
     
     
         92 . A method for modulating immune responses, comprising administering an effective amount of  claim 1  or the pharmaceutical composition thereof to a subject in need thereof. 
     
     
         93 . The method of  claim 92 , wherein the subject is a human patient having or suspected of having cancer.